In the book making arts there is known a device for assembling and depositing book signatures which typically are out transversely from a continuous band. Such a known device is operable to separate the succession of signatures from one another by an accelerating means, the signatures also being laterally adjustable relative to one another between fore-running and after-running edges, respectively, by steering-out means operable synchronically with the signature cycle. The signatures can be assembled during an assembly cycle in input compartments formed by the vanes of an impeller wheel that is driven synchronically with the assembly cycle, and can be ejected from the compartments onto a removal means, a conveyor belt, for example. To accommodate the use of the multi-compartment impeller wheel, the signature cycle is an integral multiple of the assembly cycle.
The impeller wheel of such an apparatus includes a plurality of circumferentially distributed, rigidly mounted vanes which, in conjunction with other elements, form the respective signature receiving compartments. The signature piles in the separate compartments of the impeller wheel are not supported by prior art devices either in the longitudinal or the transverse direction. Consequently, it has been virtually impossible to produce cleanly aligned inner books during the assembly of individual signatures as every single signature can slide freely in the assembly compartment during rotation of the impeller wheel and as well during the setting down of the inner book onto the removal means.
These problems are exacerbated when the signatures comprise plural folded sheets so that the possibility exists of the signatures "bulging" adjacent the folded edge of the individual sheets. This bulging effect increases with greater numbers of sheets in a signature.
Another known device comprises an impeller wheel having vanes mounted so as to be pivotable about an axis. This device, however, is a piling unit for a sheet counting apparatus and the vanes thereof are not controlled for the whole of their circumferential path but instead are primarily under the influence of centrifugal force. A pivotal control of the individual vanes is effected only to provide some limited working function, for example for the purpose of reducing the diameter of the circle on which the tips of the vanes move in operation, the purpose being to limit the space requirements of the apparatus.